Transmission for automobiles



I. E. JOHNSON.

TRANSMISSION FOR AUTOMOBILES.

APPLICATION FILED DEC-3, I920.

JPatentedSept. 19,1922,

3 SHEETS-SHEET I.

,. \N i I w I J. E. JOHNSON.

TRANSMISSION FOR AUTOMOBILES. APPLICATION nu-:0 050.3. 1920.

Patented Sept. 19, 1922.

3 SHEETSSHEET 2.

1. E. JOHNSON. TRANSMISSION FOR AUTOMOBILES. APPLICATION FILED DEC. 3. I920.

1,4293%, I teflSept. 19,1922,

3 SHEETS-SHEET?- o l wm (mm Patented Sept. 319?, i922.

PATENT @FFHGEQ I sonata. JOHNSON, or DE KALIB, rnnnrors.

TRANSMISSION FOR AUTOMOBILES.

Application filed December 3, 1920. serial No. 4.27,969.

To alzwhomtmayconcern: V Be it known thatll, JOHN E. JOHNSON, citizen of the "United States, residing at De Kalb, lllinois, have invented certain new and useful Improvements in a Transmission for Automobiles; and- I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to transmissions for connecting two rotatable parts of any mechanism, and more particularly to transmissions for connecting a continuously rotating shaft with another shaft in such a manner that the speed of the second shaft can be varied considerably. lit also aims to provide simple means for adjusting the transmission so that its effectiveness can readily be varied according to the resistance ofi'ered to the rotation of the driven shaft, and so that the transmission can also be employed as a clutch for continuously connecting the two shafts. Moreover, I aim to provide these general objects in a novel mechanism cpnstructed without any gearing and operating on a friction-gripped principle which permits'parts associated respectively with the two shafts to engage one another during adjustahly controlled portions of each revolution of the driving shaft.

While transmissions of this general class may be employed for a largevariety of pur-' poses, the transmission of my invention is particularly adapted for use upon automobiles and I am therefore illustrating it in a form suitable for such an embodiment, although I do not wish to be limited to this particular application. Further and more detailed objects of my invention will also appear from the following specifi'c'atlon and from the accompanying drawings, in which Fig. 1 is a vertical section taken along the correspondingly numbered line of Fig. 2 and showing the interior of the transmisslon Casing together with the arrangement of various parts housed by this casing.

Fig. 2 is a central. and longitudinal section through the same, taken along the correspi'indingly numbered line of Fig. 1.

Fig: is a central and longitudinal ,section taken at right angles to both Fig. 1 and Fig. 2, namely along the line 3-3 of Fig. 1..

Fig. 4 is a perspective view of one of the two drag arms which extend transversely of the driven shaft.

Fig.6 is a plan View of one of the gripper members carried by the continuously rotating casing of the transmission.

Fig. 6 is an elevation of the same.

Fig. 7 isa perspective View of one of the levers which effect the adjustment of the two drag arms.

Fig. 8 is a perspective view of one of the two slides used in connection with this adjustment, namely the slide used for rocking the lever of Fig.7.

Fig. 9 is a detail view drawn on a reduced scale and showing one pair of grippers and one of the drag arms approaching these grippers.

Fig lO is a plan view of the partsshown in Fig. 9 viewed in the direction ofthearrows in Fig. 9.

In accomplishingthe object of my inven tion according to the illustrated embodiment,l employ the principle of having the driven shaft carry a couple. of arms which project transversely outward from this shaft and which are so positioned as to pass between a series of spring-pressed grippers arranged in pairs after the manner of spring clips. These pairs of spring-pressed grippers are mounted in a casing 1 which is fastened to the driving shaft 2 and which therefore continuously rotates with this driving shaft about the common axis of both shafts. Then I provide readily operable means for. adjusting the positions of the drag arms 3 so that each of these can present portions of varying thickness between the grippers 4, thereby permitting the duration and effectiveness of the gripping to be varied at the will of the operator.

As a convenient arrangement for this latter purpose, I am here showing the casing l as constructed in two halves which in genera-l are counterparts of each other, but in which one. half is fastened to the drivin shaft 2 while the other half has at its en a bore containing a ball-bearing 5 which permits the driven shaft 6 to rotate freely with respect to the casing 1. Each half of this casing has a series of pockets 7. extending partly around it and opening throu h slots 8 into a central chamber 9 within the casing, which chamber is in alinement with the path of the drag arms 3'and of the friction portions of the grippers 4:. For the grippers, I am showing steel forgings each shaped as shown in Figures 5 and 6 and each having a lug 10 through which it is a connected by a pivot pin 11 to the adjacent sides of the pocket'7 which houses both this lug portion and the adjacent base-portion 12 of the gripper. Projecting from the base 12 in the opposite direction from the lug 10 on' each gripper is a can 13 which extends a .through the'adjacent slot 8 into the central.

chamber 9 of the transmission casing. This cam has a face It extendingoblique to the base 12 so as to present an incline to the nearer side of one of the drag arms 3 when the gripper in Fig. 9. least one spring 15 pressing against the rear of this. base, so as to urge the cam portlon of the gripper-towards themedial plane of the transmission, which plane is also the central' plane of the drag arms 3, the gripper being-limited as to its-movement in that direction by the engagement of the base 12 with the slotted portion 46 of the casing through which the cam 13 projects.

- Y The grippers as thus constructed are ar mg the driven shaft 6 which carries the drag arms. However, each of the arms 3 is so mounted that it-canbe moved longitudi-- nally or laterally outward of the driven shaft, and each of these arms has a series of successively thicker portions 17, 18 and 19 back of its extreme tip, so that any one of these thicker portions can be presented in the path of the grippers by correspondingly adjusting the position of the drag arm with respect to the axis of the transmission. Consequently, if these drag arms are moved sufliciently-to present the second portion 17 (which is slightly thicker than the normal distance between the 'faces14 of the gripper cams 13) in the path of the grippers, each opposed pair of grippers'will frictiona1ly engage this portion 17 on each drag arm for a small part of a revolution of the casing 1 towhich the grippers are pivoted; In doing so, the opposed grippers will be forced apart against the pressure of the springs back of-them, so that the action is a similar to that of a spring clip -snapping over an arm interposed in its path. Likewise, if the arms are moved further so as to approaches the latter as shown Each of these grippers has at interpose the next thicker portion 18 in the pathlof the gripper cams, these will be separated more widely,'thereby increasing the amount of friction due to the action of the springs and increasing the rotating e'fi'ect imparted through the drag arms to the driven shaft the continuous rotation of the grippers. sit-ions of the drag arms I can therefore vary both the proportionate speed at'which the driven shaft isrotated, and the amount of power transmitted. Also, by carrying this adjustment to the point where the grippers are opposite the thickest engaging portion 19 of the drag arms and by having these portions 19 of such a thickness that they jam between the opposed grippers, I can employ my transmlssion as a positive clutch, so

that my general arrangement. not-only enables me to-provide a transmission which is free from gears but also permits me to eliminate the usual clutch. l I 7 To effect the needed adjustment of the drag arms, 1' preferably provide means which can readily be operated while the fiy suitably adjusting the poparts are in rotation. For this purpose, I-

am here showing a 'de member 20;as

keyed to'the driven shaft 6, thisguide memher having slots so as to afiord slides forthe tail portions of the drag arms 3. "Each of these drag arms has atransverse bore 21 near its rear endfor permitting the entrance ofthe forked end 22 of a lever .(shown in F 7) so that the fork of the lever can engage a pin 23 which extends through the bore 21 andforms a means whereby the lever can move the arm 3 longitudinally. Each of the said levers is pivoted to a lug 24: on

the guide member 20 and has an outer'lever arm 25 extending slidably through a loop 26 I on aslide 27 which slide is shown in perspective in FigfS. The two slides as thus arranged are independently movable and extend on opposite sides of the driven shaft 6 through the ball bearing 5 as shown in Fig. 3. Also, each of these slides has at its outer end an ear -28 interposed between a pair of compression springs 29 which both bear against collars on a pin 30. Both pins 30 are Y fastened to a sleeve 31 which is slidahl.

mounted on the drit'en shaft 6 and whic can be moved longitudinally of that shaft by a control lever 32 having a forked end-in engagement with an annular groove in the sleeve 31 after the manner shown in Fig-3. By moving the control lever 32 through any suitable connections (which are not here illustrated, but whichwill readily be understood as being arranged withinreach of the driver of the vehicle) the collar 31 will therefore move both of the slides 27 longitudinally .of. the driven shaft 6, thereby rock ing the two connecting levers 25 and conespondingly'moving the dra arms 3 so as to vary the friction portions 0 the arms which respect to the axis of the transmission, but

of a number which is not a multiple of the number of drag arms, and preferably use an even number of drag arms and an odd number of pairs of grippers, so that the arms will not be simultaneously engaged but will be subjected to an intermittent frictional gripping. F or example, I am here showing the use of two drag arms in combination with. three pairs of grippers. While the grippers are engaging an arm this gripping would prevent a sliding of the gripped arm for effecting the desired adjustment, hence I interpose the springs 29 for permitting a movement of the collar 31 to compress either the inwardly or the outwardly positioned springs 29 when the collar is moved. These springs when compressed exert a pressure corresponding to the desired movement of the operating slides 27, and this movement is effected for each drag arm as soon as the latter is released from its momentary friction grip. Consequently, by using a separate lever 25 and slide 27 for each of these drag arms and by interposing the springs 29 in the operative connections, ll can readily effect the desired adjustment of these drag arms while the various parts are in motion.

To reduce the wear on the operative parts, I desirably employ drag arms and grippers of hardened steel or steel compositions, and I. also desirably fill the chamber 9 with a suitable heavy lubricant.

I also desirably curve the grippers concentrically of the shaft so that each of the cam faces of the grippers can have a long.

sliding engagement with a drag arm without requiring an unduly bulky construction. By thus using strongly built operative parts and operating my transmission on an intermittent grip and slip principle, 1 obtain an adjustable speed-reducing transmission without any small gear teeth or other fragible parts, and one which might be employed with equal advantages for other purposes than the driving of automobiles.

I claim as my invention 1. In a transmission for connecting a pair of'coaxially rotatable members, an arm extending radially of one member, and two spring pressed means carried by the other member and arranged for frictionally engaging the said arm when-between the said means while normally permitting the arm to pass between the said means.

2. In a transmission for connecting a pair of coaxial shafts, an arm transverse of one shaft, and a spring clip carried by the other shaft and having its cooperating jaws spaced longitudinally of the shaft and disposed so that the said arm can pass between the jaws and can frictionally engage the jaws while thus passing between them.

'3. A transmission as per claim 2, inv

which the arm has consecutive longitudinal portions of varying effective width, in combination with means for moving the arm transversely of the shaft carrying the same so as to vary the width of the arm portion engaged by the jaws of the clip.

4. A transmission as per claim. 2, in which the arm has consecutive longitudinal portions of varying effective width, in combination with means operable While the shafts are rotating for adjusting the position of the arm transversely of the shaft carrying the same, whereby to vary the width of the arm portion engaged by the jaws of the clips.

5. In a transmission for connecting two.

substantialy coaxial shafts, a drag member extending transversely --of one "shaft and fast thereon, and gripper means carried by the other shaft and disposed for frictionally engaging opposite sides of the drag member during separated portions of each revolution of the shaft carrying the said gripper means with respect to the shaft carrying the drag member.

6. In a transmission for connecting two substantially coaxial shafts, a drag member extending transversely of one shaft and rotating with the same, and plural spring clips carried by the other shaft and each disposed for successively gripping the drag member from both sides thereof during each revolution of the shaft carrying the said slpring clips.

7. n a transmission for connecting two coaxially rotatable members, cooperating grippers carried by one] of the members and arranged'in pairs with the gripper elements of each pair pivoted for movement towards each other and away from each other, spring means continuously urging the gripper elements of each pair towards each other, and means for limiting the approach of the said gripper elements to each other.

8. In a transmission. connecting two coaxially rotatable members, a drag arm car ried by one member and extending transversely of the commonaxis of the said memhers, means carried by the other member for intermittently frictional] y gripping the drag arm from opposite sides thereof, and! means for adjusting the effective pressure of such frictional gripping.

9. In a transmission connecting two coaxial rotatable members, a pair of springressed cams rotating with one of the memers and presenting oppositely inclinedfaces, and an arm carried by the other member and moving in a path which adaptsit intermit tently to be frictionally engaged between the said inclined faces of the cams.

10. A transmission mechanism as per claim 9, in which each of the cams is pivotally mounted, in combination with means for limiting the extent to which the spring pressure causes the cams to approach.

11. In a transmission connectingtwo coaxial rotatable members, a plurality of pairs of spring-pressed cams carried by one of the members and disposed in annular formation about the axis thereof, each pair comprising two cams having opposed faces symmetrically oblique to the medial plane of the transmission, and a plurality of drag arms projecting from the other member and rotatable substantially in the said plane.

I 12. A transmission as per claim 2, in; which the arm has portions of varying effective wldth, 1n comblnation with means operable while the shafts are rotating for adjusting the position of the arm with respect to the shaft carrying the same, whereby to vary the width of the arm portion engaged by the clip, the said means including a member slidable on the last named shaft and a lever connecting the said member with the arm.

13. In a transmission for connecting two coaxial shafts, a plurality of drag arms carried by one shaft transversely thereof and rotating with this shaft, each arm having a series of portions of successively different thickness, spring-pressed means carried by the other shaft and disposed for frictional engagement with the drag arms, and single means for moving the drag arms to vary the thickness of the latter presented for frictional engagement with the sprin -pressed means, the drag arms being separately and yieldingly connected to the said single means.

14."In a transmission mechanism as per claim 13, a guide member fast on the first named shaft and slidalbly carrying the drag arms, levers, pivoted on the guide .member and respectively connected at one end to the drag arms for sliding the latter on the guide member, a collar slidable on the said shat and separate yielding means connecting th collar with the said levers.

15. In a transmission for connecting two coaxially rotatable members, 'a drag arm the same, a casing fast on the other member and having a pair of partitions transverse of its axis of rotation, each partition having arcuate' slots concentric with the said axis, and cam means yieldingly projected through gage the drag arm.

17. A transmission as per claim 16. in which the cam means comprise'cams pivoted to the said partitions and springs continuously urging the cams through the adjacent slots. v

18. A transmission as per claim 16, in which the cam means comprise cams pivoted to the said partitions and springs continuously urging the cams through the adjacent slots and stop formations on the cams for engaging the partitions to limit the movement of the cams through the slots.

19. A transmission as per claim 15, in which the grips are symmetrically disposed with respect to the path of rotation of the drag arm and are pivoted on axes xtending parallel to the medial plane of the said path.

Signed at De Kalb, Illinois, November 27th, 1920.

JOHN E. JOHNSON.

the said slots and adapted to frictionally en 

